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Thesis Outline UC Riverside UC Riverside Electronic Theses and Dissertations Title Biologically Inspired Photocatalytically Active Membranes for Water Treatment Permalink https://escholarship.org/uc/item/4f88067q Author Kinsinger, Nichola Publication Date 2013 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA RIVERSIDE Biologically Inspired Photocatalytically Active Membranes for Water Treatment A Dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Chemical and Environmental Engineering by Nichola M Kinsinger June 2013 Dissertation Committee: Dr. David Kisailus, Chairperson Dr. Sharon Walker Dr. Mark Matsumoto Copyright by Nichola M Kinsinger 2013 The Dissertation of Nichola M Kinsinger is approved: Committee Chairperson University of California, Riverside ACKNOWLEDGMENTS First, I would like express my appreciation to my advisor Dr. David Kisailus for his guidance and support throughout my PhD research. I would also like to thank my dissertation committee members, Dr. Sharon L. Walker and Dr. Mark Matsumoto, for their advice and guidance through this process. I would like to extend my appreciation to all of the professors in the Chemical and Environmental Engineering Department and staff members for their aid and support. I am also grateful to all of the members of Dr. Kisailus’ lab group, current and former, specifically Dr. Dongsheng Li, Dr. Lessa Grunenfelder, John Johnson, Christopher Salinas, and Wenting Hou. Special thanks to the undergraduate researchers who worked with me throughout my graduate career including Ashley Wong, Fabian Villalobos, Luke Turalich, Ian Miller, Alexander Dudchenko, Kyle Nelson, Letia Solomon, Christian Alcaraz, Nataly Dakak, Pablo Cortez, and Taahira Major. I am very thankful and grateful to the Department of Defense, Office of Naval Research who funded my National Science and Engineering Graduate Fellowship which has supported me and my research during the last three years. Lastly, I would like to thank my family and friends for all of their support and encouragement specifically, my mother, Sue Kinsinger who is a strong, professional woman role model and always supports me, and my husband, Jordan Barta who also supports and encourages me to pursue my education. iv DEDICATION This dissertation is dedicated to my mother, my late father, Thomas Kinsinger, and my husband for all of their love, support, and encouragement in all of my endeavors. v ABSTRACT OF THE DISSERTATION Biologically Inspired Photocatalytically Active Membranes for Water Treatment by Nichola M Kinsinger Doctor of Philosophy, Graduate Program in Chemical and Environmental Engineering University of California, Riverside, June 2013 Dr. David Kisailus, Chairperson There is an alarming increase of a variety of new chemicals that are now being discharged into the wastewater system causing increased concern for public health and safety because many are not removed by typical wastewater treatment practices. Titanium Dioxide (TiO2) is a heterogeneous photocatalytic material that rapidly and completely mineralizing organics without harmful byproducts. TiO2 is synthesized by various methods, which lack the necessary control of crystal size, phase, and morphological features that yield optimized semiconductor materials. Mineralizing organisms demonstrate how nature can produce elegant structures at room temperature through controlled organic-mineral interactions. Here, we utilize biologically-inspired scaffolds to template the nucleation and growth of inorganic materials such as TiO2, which aid in controlling the size and phase of these particles and ultimately, their properties. Nanosized rutile and anatase particles were synthesized under solution conditions at relatively low temperatures and mild pH conditions. The effects of reaction conditions on phase and grain size were investigated and discussed from coordination chemistry and coarsening mechanisms. Photocatalytic vi characterization of TiO2 phase mixtures was performed to investigate their synergistic effect. The suspension conditions of these catalytic nanomaterials were modulated to optimize the degradation rate of organic analytes. Through the addition of an organic scaffold during the synthesis reaction, a mechanically robust (elastic) composite material containing titanium dioxide (TiO2) nanoparticles was produced. This composite was subsequently heat-treated to produce a porous, high surface area TiO2 nanoparticulate membrane. Processing conditions were investigated to characterize the growth and phase transformation of TiO2, which ultimately impacts photocatalytic performance. These bulk porous TiO2 structures can be fabricated and tailored to act as stand-alone photocatalytic membranes, eliminating the need for nanoparticle recovery systems, thereby reducing processing costs and increasing amount of viable applications of photocatalytic systems. vii TABLE OF CONTENTS ACKNOWLEDGMENTS .............................................................................................. iv DEDICATION ..................................................................................................................v ABSTRACT OF THE DISSERTATION ....................................................................... vi TABLE OF CONTENTS .............................................................................................. viii LIST OF FIGURES ....................................................................................................... xii LIST OF TABLES ..........................................................................................................xx Chapter 1. Introduction .....................................................................................................1 1.1 Motivation and Background. ..................................................................................2 1.1.1 Current Organic Contaminants and Water Resources. ....................................2 1.1.2 Current Water Treatment Technologies. ..........................................................6 1.2 Photocatalytic Oxidation of Organic Contaminants. ..............................................9 1.2.1 Historic Overview. ...........................................................................................9 1.2.2 Photocatalyst Oxidation Processes. ...............................................................10 1.2.3 Titanium Dioxide as a Photocatalyst Material. ..............................................11 1.2.4 Current Heterogeneous Photocatalytic Reactor Designs. ..............................16 1.2.5 Application of Titania nanoparticles. .............................................................17 1.3 Synthesis of Titanium Dioxide. ............................................................................21 1.3.1 Vapor Phase Synthesis. ..................................................................................21 1.3.2 Solution-based Synthesis. ..............................................................................22 1.3.3 Sintering. ........................................................................................................23 1.4 Biologically Inspired Synthesis of TiO2. ..............................................................24 viii 1.5 Objective and Scope. ............................................................................................25 1.5.1 Specific Objectives. .......................................................................................27 Chapter 2. Nucleation and crystal growth of nanocrystalline anatase rutile phase TiO2 from a water soluble precursor .......................................................................................30 Abstract ...........................................................................................................................31 2.1 Introduction ...........................................................................................................32 2.2 Preparation of materials. .......................................................................................34 2.3 Material Characterizations. ...................................................................................34 2.4 Results and Discussion. ........................................................................................35 2.4.1 Hydrothermal Conditions: pH, organometallic precursor, time. ...................36 2.4.2 Phase Development. .......................................................................................40 2.4.3 Growth Mechanism. .......................................................................................46 2.5 Conclusions ...........................................................................................................51 Chapter 3. Synergistic Effect of pH and Phase in a Nanocrystalline Titania Photocatalyst ...................................................................................................................52 Abstract ...........................................................................................................................53 3.1 Introduction. ..........................................................................................................54 3.2 Experimental. ........................................................................................................57 3.2.1 Preparation of materials. ...............................................................................57
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